Vehicle lift

ABSTRACT

A LOW PROFILE FLUID OPERATED LIFT FOR VEHICLES HAVING A WHEELED FRAME WITH A GENERALLY HORIZONTALLY DISPOSED CYLINDER CARRIED THEREBY, THE CYLINDER HAVING A PLURALITY OF INTERCONNECTED PRESSURE CHAMBERS THEREIN, THERE BEING MOVABLE MEANS CORRESPONDING TO EACH OF THE CHAMBERS, MEANS FOR INTRODUCING PRESSURIZED FLUID INTO EACH OF THE CHAMBERS SUBSTANTIALLY SIMULTANEOUSLY WHEREBY TO CAUSE THE MOVABLE MEANS TO EXERT A FORCE AS THEY ARE MOVED, THERE BEING A SHIFTABLE ASSEMBLY INTERCONNECTING THE MOVABLE MEANS IN SUCH A MANNER THAT THE RESULTANT FORCE PRODUCED UPON MOVEMENT OF THE MOVABLE MEANS AND TRANSMITTED TO THE SHIFTABLE ASSEMBLY IS THE SUM OF THE FORCES PRODUCED BY THE INDIVIDUAL MOVABLE MEANS, THE SHIFTBLE ASSEMBLY BEING COUPLED WITH MEANS FOR ENGAGING AND LIFTING A VEHICLE WHEREBY SUCH RESULTANT FORCE MAY BE UTILIZED TO LIFT THE VEHICLE. SAFETY RETAINING MEANS ARE PROVIEDE FOR HOLDING THE VEHICLE LIFT IN A RAISED POSITION REGARDLESS OF THE PRESSURE OF FLUID IN THE CHAMBERS, SAID RETAINING MEANS BEING MECHANICALLY DISENGAGEABLE TO PERMIT LOWERING OF THE LIFT.

May 23, 1972 G. L.K|NcA1b VEHICLE LIFT Filed March 23, 1970 INVEIYYOR. Gary L. BY 4 2 AT7'0RNEY5 United States Patent US. Cl. 254-8 B 4 Claims ABSTRACT OF THE DISCLOSURE A low profile fluid operated lift for vehicles having a wheeled frame with a generally horizontally disposed cylinder carried thereby, the cylinder having a plurality of interconnected pressure chambers therein, there being movable means corresponding to each of the chambers, means for introducing pressurized fluid into each of the chambers substantially simultaneously whereby to cause the movable means to exert a force as they are moved, there being a shiftable assembly interconnecting the movable means in such a manner that the resultant force produced upon movement of the movable means and transmitted to the shiftable assembly is the sum of the forces produced by the individual movable means, the shiftable assembly being coupled with means for engaging and lifting a vehicle whereby such resultant force may be utilized to lift the vehicle. Safety retaining means are provided for holding the vehicle lift in a raised position regardless of the pressure of fluid in the chambers, said retaining means being mechanically disenigageable to permit lowering of the lift.

It is the primary object of this invention to provide a fluid pressure operated lift for vehicles or the like, the fluid preferably being in the form of air under pressure which is readily available at the site of use of most vehicle lifts, the utilization of on-site air eliminating manual lifting of the vehicles or the necessity for a complex hydraulic mechanism.

It is a yet further object of this invention to provide a pressure-operated vehicle lift which has a wheeled frame, the overall height of the lift being relatively low in profile whereby the lift may be readily moved about and positioned beneath the vehicle to be lifted virtually regardless of the space available beneath said vehicle.

A still further significant object of this invention is to provide, in a low profile fluid-operated vehicle lift, safety retaining means which are automatically actuated when the lift is moved to a raised position whereby to mechanically retain the lift in such position regardless of the fluid pressure present in the lift, there being means for releasing said safety retaining assembly whereby to permit movement of the lift to a lowered position.

Other objects of the invention include details of construction which will become apparent from the following specification and accompanying drawing, wherein:

FIG. 1 is a perspective view of the vehicle lift, the handle being fragmentarily shown;

FIG. 2 is a fragmentary, central longitudinal, partially sectional view of the vehicle lift in its lowered position;

FIG. 3 is a fragmentary, partially sectional view of the vehicle lift in its raised position and particularly showing the safety retaining means; and

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2.

The vehicle lift, broadly designated by the numeral 10, includes, as its primary components, a frame 12 which carries a generally horizontally disposed cylinder 14, the cylinder being adapted to receive fluid under pressure in a manner hereinafter described. The lift is provided 3,664,635 Patented May 23, 1972 with means for engaging and lifting a vehicle, broadly designated as 16, and a handle 18 having one end thereof adjustably pivotally connected to the normally rear end 20 of cylinder 14.

The frame 12 comprises a pair of spaced-apart side members 22 being joined by a generally horizontal bridging portion 24 positioned at the uppermost substantially central area of the side members, the side members each having a forwardly extending, downwardly inclined, upper edge 26, said edges terminating at the point of juncture of side members 22 with corresponding forwardly extending members 28, said members 28 serving to support an axle support tube '30 which carries an axle '32 supporting a pair of front wheels 34 for the vehicle lift '10.

As is further evident from FIG. 1 of the drawing, the portions of side members 22 normally reanwardly of bridging member 24 each have a rearwardly extending upper edge 36, which edges 36 terminate at corresponding caster brackets 38, there being a caster bracket on each side of the frame 12, each said bracket 38 carrying a corresponding caster wheel 40. Cross struts such as 42 retain the side members 22 in their spaced-apartrelationship, said struts 42 being suitably attached, as by welding, to the side members 22 and thereby cooperating in defining the frame 12 of the lift '10.

The vehicle engaging and lifting means 16 is carried by the frame 12 and is shiftable with respect thereto from a lowered position to a raised position when the vehicle lift is actuated. The vehicle engaging and lifting means 16 includes a lift arm 44, a pair of leveling links 46, there being a link 46 on each side of the lift arm 44. At the normally forwardmost free end of the lift arm 44, there are provided vehicle engaging means in the form of a bracket 48 to which is attached a lift pad 50, the lift pad being shaped to permit suitable and secure engagement thereof with the desired portions of the vehicle to be lifted.

The bracket 48 includes a platform area '52, the platform having the lift pad 50 suitably secured thereto. Bracket 48 carries a sleeve 54 having outwardly extending ends, sleeve 54 receiving a pin 56, pivotally attaching the leveling links 46 to the bracket 48. An uppermost sleeve 58 having outwardly extending ends is also carried by bracket 48, sleeve 58 receiving a pin 60 by which lift arm 44 is pivotally attached to bracket '48.-

The lift arm 44 is pivotally attached to the frame 12 at the normally upper, rearmost portion of the lift arm by means of a transversely extending pivot pin 62, which pin 62 is journaled in bearings 64 carried by the side members 22. Side members 22 also support a pair of transversely positioned, oppositely disposed pivot pins 66 which carry the inner ends of the leveling links 46.

The means for engaging and lifting the vehicle also includes an arm 68 which is part of lift arm 44 and moves therewith through common, upper pivot pin 62, the arm 68 having its lower end coupled with a normally lowermost, transversely positioned shaft 70 upon actuation of the vehicle lift 10.

The means for coupling the operating cylinder 14 of the vehicle lift 10 with the means for engaging and lifting the vehicle 16 takes the form of at least one driving link 72, which link 72 is coupled with said means 16 by virtue of common shaft 70, the shaft 70 being secured against rotating movement by means of a locking key 74. The opposite end of the driving link 72 is pivotally attached to a lug 76 by a link coupling pin 78, it being significant that the transversely disposed pin 78, is below the central longitudinal axis of the cylinder 14. It has been found that, by careful selection of the specific pivot point locations such as 62, 70 and 78, and the angular position of the link 72, the mechanical advantage of the lift 10 can be adjusted to create an essentially constant lifting capacity throughout the entire movement of the lift to its raised position.

The interior of cylinder 14 is best illustrated in FIG. 2 of the drawing and includes, in general, a shiftable as sembly 80 which interconnects a plurality of movable means 82, 84 and 86, the movable means corresponding to a plurality of interconnected pressure chambers 88, 90 and 92, all to the end that when pressurized fluid is introduced into the pressure chambers 88, 90 and 92 at a substantially simultaneous time, the means 82, 84 and 86 will be moved to the right, viewing FIG. 2, said move ment producing a force from each movable means, the sum of such forces being transmitted to the shiftable assembly 80 which is coupled with lug 76 through nor mally forwardmost movable means 86 with the result that link 72 is shifted about the above-mentioned specifically located pivot points whereby to bring said link into compression and swing the vehicle engaging and lifting means 16 from a lowered position to a raised position.

In the embodiment of the invention chosen for illustration, the movable means 82, 84 and 86 are in the nature of a piston assembly, although it will be appreciated that other movable means, such as diaphragms, bellows and the like, might be equivalently substituted. The pistons take the form of plates 94 corresponding in cross section to the cross-sectional configuration of the cylinder 14, each of the pistons having a suitable circumscribing bearing 96. Each piston also carries an annular sealing member 98 generally channel-shaped in cross-sectional configuration and being formed of a suitable material to provide a sealing function with the interior wall 100 of the cylinder 14 and to also provide a high-lifting efficiency.

In the embodiment of the invention chosen for illustration, the interior of cylinder 14 is divided into three compartments by the presence of forwardmost bulkhead 102 intermediate bulkhead 104 and the normally rear wall 106 of the cylinder 14. The shiftable assembly 80 is in the nature of a tubular piston rod 108 disposed essentially on the longitudinal axis of the cylinder 14 and extending through bulkheads 102 and 104, the rod 108 being suitably secured to each of the piston plates 94 whereby, when said plates 94 are shifted, the rod 108 will be moved therewith.

The forwardmost piston plate 94 is rigidly secured to the normally forwardmost end of rod 108, as by welding or the like, the lug 76 also being secured to the forwardmost piston plate 94. The intermediate piston plate 94 is secured to the piston rod 108 by a two-piece, longitudinally split retainer assembly 110 acting in cooperation with a retaining ring 112. The normally rearmost piston plate 94 is secured to rod 108 by means of a split retainer 114 and bolts 116, the retainer 114 limiting the forward travel of the shiftable assembly 80 by butting against the bulkhead 104 when the shiftable assembly 80 is moved to the right, viewing FIG. 2. A retaining ring 118 is carried by the rod 108 at a position to prevent the sealing member 98 of movable means 82 from slipping off the rear end of the piston rod 108, which might occur if a user were to manually elevate the vehicle-engaging means without introducing pressurized fluid into the interconnected pressure chambers 88, 90 and 92.

The piston rod 108 has the normally rearmost end 120 thereof open, the forwardmost end being closed by a suitable plug 122 to permit the introduction of fluid under pressure at end 120 and prevent escape thereof from the other end by plug 122. A pair of radially disposed openings 124 and 126 are provided through rod 108, opening 124 corresponding to chamber 90, and opening 126 corresponding to chamber 92. Likewise, a passage 128 is provided through rear wall 106 of the cylinder 14, said passage being in communication with the interior of chamber 88 and also the interior of the tubular piston rod 108 by means of the open end 120 thereof, all to the end that when fluid under pressure is introduced into cylinder 14 through passage 128, substantially equal pressure will be essentially simultaneously deliveded into pressure chambers 88, 90 and 92 to thereby cause movement of the movable means and thus shifting of the assembly which is suitably connected to the movable means as hereinabove described.

It will be noted that the pressure chambers and 92 are formed by bulkheads 104 and 102 respectively, which cooperate with annular transversely channel-shaped sealing members 130 and 132 respectively, which cooperate with similar members 98 to define a chamber into which fluid under pressure may be delivered through openings 124 and 126 respectively.

The rear chamber 88 is defined by the cooperation of rear wall 106 of the cylinder 14 and the corresponding annular sealing member 98 which is carried by normally rearmost piston plate 94 in a manner hereinabove described. It is desirable that the rear wall 106 be provided with a lower hole 134, normally closed by a plug such as 136, to permit removal of any condensed water which may have accumulated in the pressure chamber 88 by virtue of the utilization of pressurized fluid such as air.

As hereinabove described, the pressurized fluid used in operating the vehicle lift 10 is delivered into cylinder 14 through passage 128, the passage 128 being in communication with a source of air under pressure as is conventionally provided at most service stations, the source having a hose 138 which is coupled with the handle 18 of lift 10 as by quick couplers 140, all to the end that the pressurized air may be delivered to the lift 10 and, more particularly, into a fluid passageway in the nature of a pipe 142 carried by the handle 18. A suitable manually operated valve 144 is interposed in the delivery pipe 142 whereby to permit the user of the lift to control the flow of pressurized air thereinto.

Viewing FIG. 4 of the drawing, it will be seen that the adjustable assembly 146 by which the handle 18 is swingably connected to the cylinder 14, permits the passage of air therethrough, the air following pipe 142 to its lower open end 148 where the air is delivered into a fluid passageway 150 formed in the pivot pin 152 to which the handle 18 is swingably mounted, the pivot pin being received by spaced-apart brackets 154 suitably secured to the rear wall 106 of cylinder 14.

Once the air under pressure has reached passageway 150 it then enters an orifice 156 which is in bracket 154 and in constant communication with the passage 128 in the rear wall 106 of the cylinder 14. Thus, it may be seen that, in any position of angular adjustment of the handle 18 with respect to the cylinder 14, air may be readily delivered into the series of pressure chambers which are disposed Within the cylinder 14 whereby to actuate the lift 10. As noted, flow of pressurized air or the like into the cylinder 14 is controlled by the operator thereof through valve 144. Likewise, once fluid under pressure has been delivered into the cooperating pressure chambers to raise the lift, air may be released therefrom through actuation of the valve 144 to thereby permit the lift to be moved to a lowered position assuming, of course, that the safety retaining means have been released.

In order to adjust the angularity of handle 18 with respect to the frame 12, a spring-loaded pin 158 extends transversely across the handle near pivot pin 152, the spring-loaded pin 158 being coupled with a lever 160, which lever 160 extends through the length of handle 18 terminating in a free, operating end 162 so that the lever 160 may be readily and remotely actuated by the user of the lift 10 to thereby shift the spring-loaded pin 158 from its engagement with an aperture 164 defined by one of the brackets 154 as by moving the same against a spring 166, thus permitting swinging of the handle 18 to various positions of angularity with respect to the remaining portion of lift 10, such positions being determined by the position of a plurality of apertures such as 164 in the bracket 154. When the angular position of the handle 18 is being adjusted, pivot pin 152 is free to rotate with respect to fluid passageway 168 formed in a plug 170, the passageway 168 being in communication with orifice 156. Such rotation of the pivot pin 152 is permitted by a seal 172 between the plug 170 and the pivot pin 152 which prevents escape of the pressurized fluid as it passes from the passageway 150 into passage 168.

The lift 10 is provided with a safety retaining assembly best shown in FIG. 3 of the drawing and broadl designated by the numeral 174, which assembly 174 mechanically retains the vehicle lift 10 in a raised position regardless of the pressure of the fluid within the interconnected pressure chambers 88, 90 and 92.

The safety retaining assemblies 174 consist of a pair of spaced-apart coacting locking members 176, said members being pivotally coupled to lift arm '44 by means of pivot shaft 70. A pair of spaced-apart lugs 178 are carried by the frame 12 to present, on each side of the lift, a surface which may be engaged by one of the series of notches 180 defined in the locking members 176. Thus, as the lift 10' is moved to a raised position, the lugs 178 will be engaged by one of the notches 180 thereby retaining the lift in its raised position and preventing inadvertent lowering thereof.

In order to permit lowering of the lift, a suitable release mechanism is provided for the safety retaining assembly 174, the release mechanism including a swingable, L-shaped bar 182 which is coupled with an operating handle 184, the operating handle having a finger ring 186 disposed at the other end thereof and Within easy reach of the user of the lift 10, the operating ring being preferably disposed adjacent the rear end of the cylinder 14.

As will be apparent as the lift 10 is moved to a raised position, the locking members 176 are free to swing about shaft 70 thereby moving the notches thereof along the corresponding lugs 178 due to the weight of the safety retaining assembly 174. However, should the lift be inadvertently or accidentally lowered, it will be appreciated that notches 180 will engage the lugs 178 thereby preventing the lift and the vehicle carried thereby from descending.

When it is desired to lower the lift from its raised position the same is moved upwardly until notches 180 move out of engagement with their corresponding lugs 178. Before or after raising the lift, ring 186 is grasped to pull operating handle 184 rearwardly, the same being retained in its rearward position by engagement of a shoulder 188 with the frame, this causing the L-shaped bar 182 to swing upwardly against a rod 190 carried by member 17 6, thereby swinging said members 176 to a position where notches 180 are out of engagement with lugs 178 and thus permitting lowering of the lift 10.

In operation of the lift hereinabove described, the same is moved to a position beneath a vehicle to be lifted by utilizing the handle 18 and the front wheels 34 and rear caster wheels 40 which are carried by the frame 12 of the lift 10. Once the lift has been desirably positioned, a source of pressurized fluid is then connected, through coupling 140 with the lift 10, whereby upon actuation of valve 144, fluid under pressure may be delivered through pipe 142 and the passage arrangement shown in FIG. 4 and described hereinabove, and ultimately through passage 128 into the interior of cylinder 14.

Upon introduction of the fluid under pressure into cylinder 14, the same substantially simultaneously reaches the three pressure chambers 88, 90 and 82 as by passing along the interior of piston rod 108 and through suitable openings into said chambers. Once pressurized fluid enters the three chambers, movement of the movable means 82, 84 and 86 is achieved, these components moving to the right viewing FIG. 2. Upon such movement, the shiftable assembly and, more particularly, rod 108 and lug 7-6 are shifted to the right viewing FIG. 2, such shifting movement serving to place link 72 in compression and causing swinging of the lift arm 44 about pivot pin 62, said swinging movement of the lift arm 44 causing a commensurate upward movement of the vehicle engaging and lifting means 16.

A continuing, substantially constant upward lifting force is exerted on the vehicle engaging and lifting means 16 through the cylinder assembly 14 and linkage hereinabove described until such time as said lifting means has reached its fully extended condition or until such time as the supply of pressurized fluid thereto is terminated by valve 144.

When it is desired to bring the lift 10 to a lowered position, it is only necessary to reverse the valve 144 whereby pressurized fluid, which is contained within the cylinder 14, and the components thereof, is permitted to escape to the atmosphere through a suitable exhaust port provided therefor. When this occurs, and assuming that the safety retaining assembly has been previously moved to a position to permit the same, the lift will be permitted to swing to a lowered position.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

'1. A wehicle lift comprising;

a frame;

a cylinder carried by said frame and having a plurality of interconnected pressure chambers therein; movable means corresponding to each of said chambers;

means for introducing pressurized fluid into each of said chambers, said pressurized fluid reacting against each of said movable means to produce a force, and thereby move the movable means;

a shiftable assembly interconnecting said movable means in such a manner that the resultant force produced by said shiftable assembly upon movement of said movable means is the sum of the forces produced by said movable means;

means for engaging and lifting a vehicle; and

means for coupling said shiftable assembly with said vehicle engaging and lifting means, said coupling means including a link having one end coupled with said shiftable assembly and the other end connected to said vehicle engaging and lifting means.

2. A vehicle lift as set forth in claim 1, said link being in compression when said lift is actuated and lifting a vehicle.

3. A vehicle lift as set forth in claim 1, said link being coupled with said shiftable assembly at a point below the longitudinal axis of said cylinder.

4. A vehicle lift as set forth in claim 3, said means for engaging and lifting a vehicle having a pivotal attachment to said frame at a point above the axis of symmetry of said cylinder and being driven by said link.

References Cited UNITED STATES PATENTS 3,181,836 5/1965 Arnes et a1. 2548 B 3,554,088 1/1971 Bruyn 92-411 3,485,141 12/1969 Ott et a1 92-111 X 3,430,539 3/1969 Freeman 921ll X 3,521,861 7/ 1970 Frevdenthal et a1. 2548 BX FRANCIS S. HUSAR, Primary Examiner D. R. MELTON, Assistant Examiner US. Cl. X.R. 25493 H 

